Topic: compressor query : what does the #'s in x:x:x (i.e. 1:3:1) stand for?

[ellaguru]

hello all...looking for some advice on using my compressors (both daw and outboard)...

i see alot of talk as i research about the 'ratio' and i have that control knob on my dbx 266xl...what do those numbers and ratios stand for? 

any other compressor advice is welcome...i have some multi tracks that need a little tlc for mixdown and im kinda lost as where to start,

thanks

chris

[Chuck]

That's a logarithmic ratio. 1.3:1 = 1.3 to 1
So, there is a huge difference between 2:1 and 10:1.
At 10:1 and above a compressor acts like a limiter. Meaning there is very little gain change above the knee.

Start with as little compression as possible 1.3:1 to 2:1 is a good starting point, of course depending on the instrument (track) you are using it on. A little compression can go a long way. Use your ears, rather than the compression ratio numbers to determine what works best. There is usually a make up gain control that you can use to bring the level back up after running the track through the compressor.

[ellaguru]

ok...thanks chuck..but what about in reaper (or any other daw) where i dont have a 'ratio' adjustment setting?  i understand attack/release, but im just a tad confused as to what im actually doing/changing by messing with settings like threshold, and amount.   in reaper i use the sony fx plug in..

thanks again

chris

[Patrick]

ok...thanks chuck..but what about in reaper (or any other daw) where i dont have a 'ratio' adjustment setting?  i understand attack/release, but im just a tad confused as to what im actually doing/changing by messing with settings like threshold, and amount.   in reaper i use the sony fx plug in..

thanks again

chris

Threshold is the point at which compression is applied to the signal.  The lower the threshold, the more dynamic range is lost.  I've never used Reaper, but "amount" is most likely referring to Ratio.  For audience tapes, keep this lower as you don't want to have the compressor "pump" as the music is playing.  Like Chuck said, stay in the 2:1 neighborhood, as a general rule.

In other words, every time your signal goes ABOVE your threshold, the compressor is going to reduce dynamic range of the signal by a certain RATIO (amount), and will apply this compression according to the times specified by your attack and release controls.

Stare at this for a minute and it may be helpful

[Chuck]

ellaguru, sorry to give you such a short answer. I had a longer answer, but I lost track of time and had a meeting I had to attend.

I found a nice, well written source for answers to your questions online:

http://en.wikipedia.org/wiki/Dynamic_range_compression

The Basics section has a very good explanation of what compression is and what compression ratios are.

That, along with what Patrick posted should give you a better understanding of what the ratios actually mean.


...edit to add: Sorry, but I'm not familiar with the Sony plug-in you mentioned.

[ellaguru]

^^ thanks to all for the help

[Todd R]

What do folks who use compression on their 2 track recordings of PA-driven concert material typically use for settings?

I'm assuming that in this application, the FOH engineer is already using a variety of limiters and compressors.  For 2ch "mastering" of recordings, if I use any compression at all, I use something like a 1.3:1 ratio or 1.4:1, kicking in at somewhere between -8db or -12db.  So meaning, really not much compression at all.

2:1 is pretty light compression I guess, but I've never even tried going anywhere near that far, and don't think I've gone any more (less? depends on definition) than a threshold of -12db.

[Chuck]

What do folks who use compression on their 2 track recordings of PA-driven concert material typically use for settings?

I'm assuming that in this application, the FOH engineer is already using a variety of limiters and compressors.  For 2ch "mastering" of recordings, if I use any compression at all, I use something like a 1.3:1 ratio or 1.4:1, kicking in at somewhere between -8db or -12db.  So meaning, really not much compression at all.

2:1 is pretty light compression I guess, but I've never even tried going anywhere near that far, and don't think I've gone any more (less? depends on definition) than a threshold of -12db.

I have only recently started to do any compression or in my case maximization/optimization on any of my recordings. 
I've wrestled with that decision for a while. I'm reluctant to even EQ recordings, because I still have a bit of the purist mentality as far as recordings go. I use WAVES L1/L2 at work for speech recordings, and in the past I thought I heard distortions introduced by it. But, after spending some time experimenting, I've started to use it to knock down some of the extreme peaks in some recordings. I have not applied traditional compression to any of my  recordings yet. To me, that's more of a mastering function, like stereo EQ, so I don't really mess with it unless it's absolutely necessary.

Like Todd says, the FOH guy is already compressing the sound enough... and some engineers really over do it already.

[ellaguru]

my compressor needs are for live multi track recordings.  mainly on the vocals

[ArchivalAudio]

ellaguru, sorry to give you such a short answer. I had a longer answer, but I lost track of time and had a meeting I had to attend.

I found a nice, well written source for answers to your questions online:

http://en.wikipedia.org/wiki/Dynamic_range_compression

The Basics section has a very good explanation of what compression is and what compression ratios are.

That, along with what Patrick posted should give you a better understanding of what the ratios actually mean.


...edit to add: Sorry, but I'm not familiar with the Sony plug-in you mentioned.

that's a great compression wiki
I have read a lot and played with compression mostly as FOH with vox and drums
but that's a great explanation...

and to the loudness war link which I have seen before:
here:

http://en.wikipedia.org/wiki/Loudness_war
thanx

[kirk97132]

FWIW,  If settings get higher a compressor can take on a breathing sort thing.  (usually over 3:1) The best examples I can think of are newscasts which have been highly compressed.  with that said, it all depends on what you are trying to accomplish.  Since all the OP stated was wanting to know what the ratio numbers were.  There are other options like expanders & limiters which might be of some use too.  And there has been no mention if it is a multiband compressor or just a single band compressor and if it is a tube modeled type or what kind of compressor and/or program that is being dealt with.   

The ratio in it's strictest sense is what is being return against the input.  IE: 3.0:1 means that for ever three units of input the compressor returns one unit.  But none of this addresses, gain, level, attack & release.  All of which have bearing. 

[rastasean]

chuck,
when you do your compressions, are you doing it per track or the entire recording at one time?

[Gutbucket]

What do folks who use compression on their 2 track recordings of PA-driven concert material typically use for settings?

I have only recently started to do any compression or in my case maximization/optimization on any of my recordings. 
I've wrestled with that decision for a while..

For live music recordings, I use compression to bring up the quiet details, rather than push down the loud peaks - In that sense I'm using it more like a mastering tool.  Search New York compression or Parallel Compression for an explaination of bottom-up compression.  It is far, far more natural sounding and easier to get a good result than trying to insert a typical compressor across the stereo buss and sending everything through it.  I'll manually trim large peaks here and there to get the RMS level somewhere managable, but I find regular compression or limiting seems to kill what I'm going for, where as parallel compression used in moderation and applied with a critical ear, makes me smile.  It's like turning up the volume to hear the detailed bits, without messing up the dynamic transients and the louder portions of the program.

[kirk97132]

Gutbucket, So in essence you are making it an expander rather than a compressor right?  Have you tried using an expander instead?  And I totally agree with you about doing parallel tracks for effects, it yields better results for me and my inexperienced methods

[Chuck]

chuck,
when you do your compressions, are you doing it per track or the entire recording at one time?

I don't use traditional compression on my live to two track recordings now. But, I have been using the WAVES L2 (maximizer) on occasion.

When I did live sound, I used compressors and at work I use them to limit the dynamic range of audio presentations so they can be heard better on a phone.

I haven't had the right opportunity yet to use my DR-680 to record all the instruments on separate tracks and mix them down later. When the opportunity comes up, I'll most likely use compressors on some of those tracks in mix down.